Prism4 概述
最近一直在看Prism的资料，希望能和大家一起分享学习的成果。由于我也是第一次碰Prism，所以不足之处还请大家指正。
园子已经有一位前辈牛人写过Prism的系列教程了，我觉得写得不错：
http://www.cnblogs.com/Clingingboy/archive/2009/06/01/prsim_tutorial.html
我没有园子里很多牛人的写作功底，所以文章不会那么细致，主要是抛砖引玉的作用，嘿嘿。
Prism是什么，能做什么
Prism是微软针对WPF,Silverlight以及Windows Phone推出的一套框架，可以帮助开发着轻松解耦自己的项目。Prism也有一些AOP的元素在里面，比如日志记录，但是Prism的主旨还是模块化程序。Prism提供了很多种手段进行注入，模块的动态加载，UI组合，命令系统，MVVM模式扩展等等，下面是Prism的功能比较全面的介绍：
bootstrapper. The class responsible for the initialization of an application built using the Prism Library.
command. A loosely coupled way for you to handle user interface (UI) actions. Commands bind a UI gesture to the logic that performs the action.
composite application. A composite application is composed of a number of discrete and independent modules. These components are integrated together in a host environment to form a single, seamless application.
composite command. A command that has multiple child commands.
container. Provides a layer of abstraction for the creation of objects. Dependency injection containers can reduce the dependency coupling between objects by providing the facility to instantiate instances of classes and manage their lifetime based on the configuration of the container.
DelegateCommand. Allows delegating the commanding handling logic to selected methods instead of requiring a handler in the code-behind. It uses .NET Framework delegates as the method of invoking a target handling method.
EventAggregator. A service that is primarily a container for events that allows publishers and subscribers to be decoupled so they can evolve independently. This decoupling is useful in modularized applications because new modules can be added that respond to events defined by the shell or other modules.
modularity. The ability to create complex applications from discrete functional units named modules. When you develop in a modularized fashion, you structure the application into separate modules that can be individually developed, tested, and deployed by different teams. It also helps you address separation of concerns by keeping a clean separation between the UI and business functionality.
model. Encapsulates the application's business logic and data.
module. A logical unit of separation in the application.
ModuleCatalog. Defines the modules that the end user needs to run the application. The module catalog knows where the modules are located and the module's dependencies.
ModuleManager. The main class that manages the process of validating the module catalog, retrieving modules if they are remote, loading the modules into the application domain, and invoking the module's Initialize method.
module management phases. The phases that lead to a module being initialized. These phases are module discovery, module loading, and module initialization.
multi-targeted code. Code that targets two different platforms with largely the same code-base. This allows binaries targeting two different technologies to be produced while keeping the code as much the same as possible. The technologies that Prism helps you multi-target are Windows Presentation Foundation (WPF) and Silverlight.
navigation. The process by which the application coordinates changes to its UI as a result of the user's interaction with the application, or as a result of internal application state changes.
presenter-first composition. The composition approach where the presenter is logically created first, followed by the view.
on-demand module. A module that is retrieved and initialized only when it is explicitly requested by the application.
region. A named location that you can use to define where a view will appear. Modules can locate and add content to a region in the layout without exact knowledge of how and where the region is visually displayed. This allows the appearance and layout to change without affecting the modules that add the content to the layout.
RegionContext. A technique that can be used to share context between a parent view and child views that are hosted in a region. The RegionContext can be set through code or by using data binding XAML.
RegionManager. The class responsible for maintaining a collection of regions and creating new regions for controls. The RegionManager finds an adapter mapped to a WPF or Silverlight control and associates a new region to that control. The RegionManager also supplies the attached property that can be used for simple region creation from XAML.
Separated Presentation pattern. Pattern used to implement views, which separates presentation and business logic from the UI. Using a separated presentation allows presentation and business logic to be tested independently of the UI, makes it easier to maintain code, and increases re-use opportunities.
shell. The main window of a WPF application or the top-level UserControl of a Silverlight application where the primary UI content is contained.
scoped region. Regions that belong to a particular region scope. The region scope is delimited by a parent view and includes all the child views of the parent view.
service. A service provides functionality to other modules in a loosely coupled way through an interface and is often a singleton.
state-based navigation. Navigation accomplished via state changes to existing controls in the visual tree.
UI composition. The act of building an interface by composing it from discrete views at run time, likely from separate modules.
view. The main unit of UI construction within a composite UI application. The view encapsulates the UI and UI logic that you would like to keep as decoupled as possible from other parts of the application. You can define a view as a user control, data template, or even a custom control.
view-based navigation. Navigation accomplished via the addition or removal of elements from the visual tree.
view-first composition. The composition approach where the view is logically created first, followed by the view model or presenter on which it depends.
view discovery. A way to add, show, or remove views in a region by associating the type of a view with a region name. Whenever a region with that name displays, the registered views will be automatically created and added to the region.
view injection. A way to add, show, or remove views in a region by adding or removing instances of a view to a region. The code interacting with the region does not have direct knowledge of how the region will handle displaying the view.
view model. Encapsulates the presentation logic and state for the view. It is responsible for coordinating the view's interaction with any model classes that are required.
大家可以看到，Prism4 给我们提供了非常多的功能让我们完善自己的应用。
Prism与容器以及其他工具
Prism与容器的关系不得不说一下，Prism是基于依赖注入容器的，目前Prism4提供了两种容器支持，一种是Unity，一种MEF，两种容器的功能相似，但是还是有区别的，Unity可以与EntLib结合，实现AOP功能，我觉得这个很诱人，而MEF嵌入在.net框架里，并且可以自动发现程序集，下载XAP等等功能。在Silverlight和Windows Phone中我更倾向于使用MEF，减小了发布程序集的大小，同时AOP在Silverlight和Windows Phone上的意义不大，当然，也只是我一家之言而已。WPF中我更倾向于使用Unity结合EntLib来做更多的工作。
我将介绍什么
作为一个初学者，很抱歉我也很难给大家提供太多有价值的信息，但是我会尝试给没有接触过Prism的同学一个对Prism完整的印象。
- 模块化，模块加载
- 依赖注入
- 启动与程序初始化
- UI组合
- 命令系统
- 使用MEF容器
- 导航
以后是不是还会有其他内容就不得而知了，呵呵。
唉，先抱歉一声，因为我还在上学，更新日志的时间不定，呵呵，什么时候写完就不好说了。
最后，祝大家每天好运哦！
